“Open Source” advocate: «...I associate much more with the "Open Source" (also as Richard defines it) camp, and am open to the existence and use of proprietary software...» --

"Open source is a development methodology; free software is a social movement. For the free software movement, free software is an ethical imperative, because only free software respects the users' freedom. By contrast, the philosophy of open source considers issues in terms of how to make software “better”—in a practical sense only. It says that non-free software is a suboptimal solution.

The methodologies of Open Source are not owned or guided by any one person. The closest thing we have are the Open Source Initiative (OSI) and support of the Free Software Foundation (FSF). The OSI certifies what qualifies as an open source license.

«...On this subject, I had an interesting email conversation with Richard Stallman, founder of the Free Software Foundation, who differentiated for me the difference between "open source" and "free software," ...» -- Free Software, Free Society: Why Barack Obama should support the Free Software Movement

In our earlier article, "Facts and Friction on Open Source and Free Software" we have explained where "Open Source" is coming from and what is its relation to Free Software and the Free Software Foundation that represents it.

most free software is free in the monetary sense of the word ("gratis"), which can be a hindrance to those of us who are trying our best to emphasize the "freedom-as-in-liberty" sense of free software to those who don't yet understand.

"..RMS’s other mission here is to promote the Free Software Movement. The creator of the GPL...is at pains to correct misunderstandings of what the term free software means and to draw a distinction between it and the open source movement.

"Ordinarily, when you think of the phrase ‘free software’, the definition that comes to mind is a piece of tool that can be used or modified freely without any restriction.

Free Software developers fall into two main categories: those that stand by the principles behind free software - patent-free, license-free and unrestricted distribution and those that are simply happy to compromise to some extent, for example to download libdvdcss to watch DVDs, or to install proprietary software such as Skype, on the basis that there is simply no (or no better) alternative